What this means
The IEEE assigned the MA-L block 10003B to Espressif Inc.. Every network interface they manufacture under this block has a MAC address beginning with these digits, followed by a unique per-device identifier. If a device on your network shows a MAC starting 10:00:3B, it is Espressif Inc. hardware.
Frequently Asked Questions
Who owns MAC prefix 10003B?
10003B is registered to Espressif Inc. in the IEEE MA-L registry.
What does the MA-L registry type mean?
An MA-L assignment, the IEEE's original OUI format, gives the vendor the first three octets and 16,777,216 device addresses under them. Espressif Inc.'s block covers 16,777,216 addresses.
What devices use 10003B?
Any network device with a MAC address starting 10:00:3B was manufactured by or for Espressif Inc..